SACCHARIFICATION OF CASSAVA FLOUR STARCH IN A HOLLOW-FIBER MEMBRANE REACTOR

The enzymatic saccharification of cassava flour starch with Aspergillu s niger glucoamylase was studied in a hollow-fiber enzymatic membrane reactor (HF-EMR). The optimization of the process was also investigate d. The substrate was previously gelatinized by extrusion that produced a substrate with a degree of gelatinization and physical properties s uitable for the enzymatic process. Typically, continuous saccharificat ion of cassava flour starch in the HF-EMR produced a highly pure produ ct in permeate (i.e., 99.6% glucose) with a global starch to glucose c onversion of 97.3%. Results from a factorial experimental design revea led that retention time, enzyme to substrate ratio, and substrate conc entration were the variables that most affected the process for starch to glucose conversion and for solid accumulation rate. Empirical mode ls that describe this process were experimentally determined and compa red with a theoretical model based on a balance of materials and enzym e kinetics. They wee shown to adequately predict the performance of th e HF-EMR. (C) 1997 Elsevier Science Inc.